Related papers: Where is the pi particle?
Inelastic neutron scattering was used to study the wavevector- and frequency-dependent magnetic fluctuations in single crystals of superconducting YBa$_2$Cu$_3$O$_{6+x}$. The spectra contain several important features, including a gap in…
We have mapped from the quantum to the classical limit the spin excitation spectrum of the antiferromagnetic spin-1 Heisenberg chain system CsNiCl3 in its paramagnetic phase from T=5 to 200K. Neutron scattering shows that the excitations…
Phenomena of rotation and oscillations of particle spin are discussed for particles rotating in storage ring. The fact that these effects are described by spin-dependent part of zero-angle scattering amplitude allows to use them for the…
We study the plasma branch of an homogeneous three-dimensional electron gas in an $s$-wave superconducting state. We focus on the regime where the plasma frequency $\omega_p$ is comparable to the gap $\Delta$, which is experimentally…
Within the t-t'-J model, the asymmetry of the electron spectrum and quasiparticle dispersion in hole-doped and electron-doped cuprates is discussed. It is shown that the quasiparticle dispersions of both hole-doped and electron-doped…
Pion elastic, charge exchange scattering and induced eta production on the trinucleon systems are investigated in a coupled-channels approach in momentum space with Fadeev wave functions. The channel $\pi N \rightarrow \eta N$ is included…
The recently discovered enhancement of eta photoproduction on the quasi-free neutron at energies around s^1/2 ~ 1.67 GeV is addressed within an SU(3) coupled channels model. The K Sigma threshold plays a significant role and the quasi-free…
There is ${}^3P_2$ neutron superfluid region in NS (neutron star) interior. For a rotating NS, the ${}^3P_2$ superfluid region is like a system of rotating magnetic dipoles. It will give out electromagnetic radiation, which may provides a…
In this paper we investigate the effect of a pinned superfluid component on the gravitational wave emission of a steadily rotating deformed neutron star. We show that the superfluid pinning allows the possibility for there to be…
Recent experiments on single crystals of YNi$_2$B$_2$C have revealed the presence of point nodes in the superconducting energy gap Delta(k} at k = (1,0,0), (0,1,0), (-1,0,0), and (0,-1,0). In this paper we investigate the effects of…
Pion production at threshold from nucleon-deuteron collisions is considered, with reference to the outgoing channel where the three-nucleon system is bound. The available experimental data are compared with calculations using accurate…
The numerically exact diagonalization study on small clusters of the t-J model with the second- and third- neighbor hopping terms shows that a novel spin liquid state is realized around a doped hole with momentum k=(pi,0) and energy \sim 2J…
We use inelastic neutron scattering to study energy and wave vector dependence of the superconductivity-induced resonance in hole-doped Ba$_{0.67}$K$_{0.33}$(Fe$_{1-x}$Co$_{x}$)$_{2}$As$_{2}$ ($x=0,0.08$ with $T_c\approx 37, 28$ K,…
The unusual dispersion of electron states in antinodal direction for $n_{h}\simeq\frac{1}{8}$ holes/copper is explained. In photoelectron excitations, transformations of the $\mathbf{k}$ space as a consequence of symmetry breaking proves to…
In the quest for superconductors with high transition temperatures (T$_\mathrm{c}$s), one emerging motif is that unconventional superconductivity is enhanced by fluctuations of a broken-symmetry phase near a quantum-critical point. While…
The pd <--> pi+ t process has been calculated in the energy region around the Delta-resonance with elementary production/absorption mechanisms involving one and two nucleons. The isobar degrees of freedom have been explicitly included in…
A universal high energy anomaly in the single particle spectral function is reported in three different families of high temperature superconductors by using angle-resolved photoemission spectroscopy. As we follow the dispersing peak of the…
The experimental data on pi N scattering in the elastic energy region T_pi < 250 MeV are analyzed within the multichannel K-matrix approach with effective Lagrangians. Isospin invariance is not assumed in this analysis and the physical…
We have updated our multipole analyses to incorporate new data from the low-energy and delta resonance regions. We note a slight decrease in our estimate of the delta photo-decay amplitudes. This agrees with results found in Compton…
Photodisintegration of the deuteron above pi-threshold is studied in a coupled channel approach including N Delta- and pi d-channels with pion retardation in potentials and exchange currents. A much improved description of total and…